JP2007155572A - Monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring device for obtaining a monitoring image of excellent image quality. <P>SOLUTION: The monitoring device comprises a light transmitting part 11 for emitting laser light, and a light receiving part 12 for outputting to convert taken-in reflection light into an image signal by receiving the reflection light reflected by reaching a monitoring object by light emitted from the light transmitting part 11. There is provided the monitoring device provided with a light transmitting lens control part 27 for regulating an irradiation region of the light transmitting part 11 on the basis of a monitoring angle of the light receiving part 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a monitoring device that monitors an obstacle or the like in a ship or the like.

Conventionally, there is a monitoring device using a laser radar as a monitoring device that is installed in a ship or the like and detects an object over a wide range (see, for example, Patent Document 1).
For example, as shown in FIG. 10, such a monitoring apparatus using a laser radar displays a laser radar 51, a laser radar control unit 52 that controls the laser radar 51, and an image signal obtained by the laser radar 51. And a display unit 53. The laser radar 51 has a configuration in which the angle of attack and the rotation angle are controlled by a convolution table 54.
In such a configuration, at the time of monitoring, pulse laser light is emitted from the laser head in the laser radar 51 to the periphery of the ship, and this laser light reaches the monitoring target A and the reflected light is reflected by the laser radar 51. An image is picked up by the light receiving unit provided in the inside, and this image signal is output to the display unit 53, whereby an object (here, the monitoring target A) existing around is displayed on the display unit 53.
JP 2002-162466 A (page 2-4, FIG. 1)

  However, in the above-described monitoring apparatus, even if the distance to the monitoring target A changes, the setting of the light transmitting unit or the light receiving unit is not adjusted in conjunction with the change. However, there is a problem that the image quality of the monitoring image is greatly different depending on the case. In addition, since the light transmitting unit that emits the laser light and the light receiving unit that captures the reflected light of the laser light are not linked, there is a problem that an image cannot be acquired with an optimal setting.

  The present invention has been made to solve the above problems, and it is an object of the present invention to provide a monitoring apparatus capable of obtaining a monitoring image with good image quality.

In order to solve the above problems, the present invention employs the following means.
The present invention receives a reflected light reflected by a light transmitting means for emitting a laser beam and light emitted from the light transmitting means reaching a monitoring target, and converts the captured reflected light into an image signal. A monitoring device including a light transmission control unit that adjusts an irradiation area of the light transmission unit based on a monitoring field angle of the light reception unit.

  According to the said structure, the laser beam radiate | emitted from the light transmission means reaches | attains the monitoring object, and is reflected. This reflected light is received by the light receiving means, further converted into an image signal and output. In this case, since the irradiation area of the light transmission means is adjusted by the light transmission control means based on the monitoring field angle of the light receiving means, it is possible to irradiate light to a suitable area according to the monitoring angle of view. . As a result, the image signal obtained by the light receiving means can be an image signal with an optimum image quality, and a monitor image with a good image quality can be obtained by displaying this image signal on a display device or the like.

  In the monitoring apparatus, the light receiving unit includes a light receiving shutter provided on the optical path of the reflected light and opened and closed at a predetermined timing, and the light transmitting unit emits continuous light, and the laser light source. It is good also as having the light transmission shutter provided on the optical path of the continuous light radiate | emitted from, and opened and closed in synchronization with opening and closing of the said light reception shutter.

According to such a configuration, the opening / closing timing of the light transmitting shutter and the light receiving shutter is controlled in synchronization, so that the laser light can be emitted from the light transmitting means at the timing when the reflected light is received by the light receiving means. It becomes possible. Thereby, light can be emitted efficiently.
As the light source, for example, a semiconductor laser can be employed. By using a semiconductor laser, it is possible to reduce the size of the apparatus and reduce the cost while stabilizing the output.

  The monitoring device may further include a light receiving control unit that adjusts a monitoring field angle of the light receiving unit based on a distance to the monitoring target.

  According to the above configuration, by adjusting the monitoring field angle of the light receiving unit by the light receiving control unit, it becomes possible to set the field angle of the light receiving unit to a suitable monitoring field angle corresponding to the distance to the monitoring target. . As a result, the image signal obtained by the light receiving means is acquired by the optimum monitoring field angle set according to the distance to the monitoring target and the optimum irradiation region set according to the monitoring field angle. Therefore, by displaying this image signal on a display device or the like, it is possible to obtain a monitoring image with a suitable image quality.

  The monitoring apparatus having the above-described configuration includes an evaluation unit that performs noise evaluation of the image signal output from the light receiving unit, and the light transmission control unit and / or the light reception control unit is in accordance with a result of noise evaluation by the evaluation unit. Thus, the irradiation area of the light transmitting means and / or the monitoring field angle of the light receiving means may be adjusted.

According to the above configuration, the noise evaluation of the image is performed based on the image signal output from the light receiving unit by the evaluation unit. Then, the light transmission control means and / or the light reception control means can reduce the noise of the monitoring image by adjusting the irradiation region and / or the monitoring angle of view so that the result of the noise evaluation is improved. It becomes. Thereby, the image quality of the monitoring image can be further improved.
The light transmission control unit and / or the light reception control unit, for example, as a result of noise evaluation by the evaluation unit, for example, an S / N (Signal to Noise ratio) ratio is set to be higher than a preset S / N ratio. In addition, the irradiation area and / or the monitoring angle of view may be adjusted.
Alternatively, the light transmission control means and / or the light reception control means accumulates the result of noise evaluation (for example, S / N ratio) when the setting of the irradiation area and / or the monitoring angle of view is changed in stages, and the The irradiation area and / or monitoring angle of view when the S / N ratio is the highest among them may be determined, and monitoring may be performed using this irradiation area and / or monitoring angle of view.

  According to the monitoring apparatus of the present invention, there is an effect that a monitoring image with good image quality can be obtained.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing the overall configuration of the monitoring apparatus according to the first embodiment of the present invention.
As shown in FIG. 1, the monitoring device according to the present embodiment includes a laser radar 1, a laser radar control unit 2, a control device 3, and a display device (display means) 4.

The laser radar 1 includes a light transmitting unit (light transmitting unit) 11 and a light receiving unit (light receiving unit) 12.
The light transmission unit 11 is emitted from, for example, a laser oscillator (laser light source) 111 that emits continuous laser light, a light transmission shutter 112 provided on the optical path of the laser light emitted from the laser oscillator 111, and the laser oscillator 111. A light-transmitting lens 113 that expands the laser light guided through the light-transmitting shutter 112 and outputs it to the outside, and a light-transmitting lens actuator (not shown) for adjusting the position of the light-transmitting lens 112 It is provided as a main component.
The laser oscillator 111 is a small laser light source such as a semiconductor laser, for example. The laser oscillator 111 is supplied with power from a laser power source 26 in the laser radar control unit 2 described later, and emits laser light that is continuous light.
The light transmission shutter 112 is provided between the laser oscillator 111 and the light transmission lens 113 and is controlled to be opened and closed in synchronization with a light receiving shutter 122 provided in the light receiving unit 12 described later. Specifically, opening / closing control is performed by a shutter control unit 24 in the laser radar control unit 2 described later.
The light transmission lens actuator adjusts the position of the light transmission lens 112 based on a control signal supplied from a light transmission lens control unit (light transmission control means) 27 in the laser radar control unit 2 described later. Thereby, it is possible to adjust the irradiation area of the light that passes through the light transmission lens 112 and is radiated to the outside in a desired range.

The light receiving unit 12 includes, for example, a zoom lens 121, a light receiving shutter 122, and an ICCD (image intensifier CCD) camera head 123. The zoom lens 121 condenses the reflected light emitted from the light transmitting unit 11 and reflected by the monitoring target and guides it to the light receiving shutter 122. The direction of the zoom lens 121 is adjusted based on a control signal supplied from a zoom lens control unit (light reception control unit) 28 provided in the laser radar control unit 2 described later. The light receiving shutter 122 is constituted by, for example, a high-speed gate device that can be opened and closed at high speed, and is driven by a shutter control unit 24 provided in a laser radar control unit 2 described later, and is guided by a zoom lens 121. The incident light is turned on / off to the ICCD camera head 123. The ICCD camera head 123 converts the captured light into an electrical signal to generate an image signal, and outputs the image signal to the image processing device 25 in the laser radar control unit 2.
Such a laser radar 1 has a structure in which the rotation angle and the attack angle are adjusted to desired angles by the swivel base 5.

The laser radar control unit 2 controls the light transmitting unit 11, the light receiving unit 12, and the swivel base 5 of the laser radar 1 based on various control signals supplied from the control device 3. The laser radar control unit 2 includes, for example, a turntable drive unit 21, a control signal conversion device 23, a shutter control unit 24, an image processing device 25, a laser power source 26, a light transmission lens control unit 27, a zoom lens control unit 28, and the like. I have.
The control device 3 generates various control signals for controlling the laser radar 2, outputs the generated various control signals to the laser radar control unit 2, and displays the monitoring results supplied from the laser radar control unit 2 as a display device Output to 4. The control device 3 is connected to an input device (not shown), and supplies information input from the input device to the laser radar control unit 2.
The display device 4 includes a display monitor (not shown) that displays the monitoring result input from the control device 3.

The laser radar control unit 2 and the control device 3 described above are, for example, a CPU (Central Processing Unit), an HD (Hard
A computer system including a Disc), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like is incorporated. A series of processing steps for realizing various functions to be described later are recorded in the form of a program on an HD or a ROM, and the CPU reads the program into the RAM and executes information processing / calculation processing. Thus, various functions described later are realized.

Next, the operation of the monitoring apparatus according to this embodiment will be described.
First, at the time of monitoring, when a monitoring field angle is input from an input device (not shown), the control device 3 supplies information on the monitoring field angle to the laser radar control unit 2. Further, the control device 3 generates a synchronization signal and outputs it to the laser radar control unit 2.

Information on the monitoring angle of view output from the control device 3 is supplied to the light transmission lens control unit 27 and the zoom lens control unit 28 in the laser radar control unit 2.
The light transmission lens control unit 27 sets an irradiation region suitable for the monitoring angle of view acquired as input information, and sets the position of the light transmission lens 112 of the light transmission unit 11 so that light is emitted to the set irradiation region. Adjust. Specifically, the light transmission lens control unit 27 generates a drive signal for moving the light transmission lens 112 to a position where an optimum irradiation area can be obtained with respect to the monitoring field angle, and this drive signal is illustrated in the figure. Not output to the light transmission lens actuator. As a result, the position of the light transmission lens 112 is adjusted so as to be an optimum irradiation region with respect to the monitoring field angle.

  Regarding the setting of the irradiation area suitable for the monitoring angle of view, for example, the light transmission lens control unit 27 has a table in which the monitoring angle of view is associated with the irradiation area suitable for it, and this table is referred to. Thus, an irradiation area suitable for the monitoring angle of view may be set. Alternatively, in place of the above-described table, a table in which the monitoring angle of view and the position of the light transmission lens 112 are directly associated is held, and the position of the light transmission lens 112 is directly acquired from this table. It is good also as a simple structure. An example of a table in which the monitoring angle of view is associated with the light transmission lens 112 is shown in FIG. In FIG. 2, the vertical axis represents the position of the light transmission lens 112, and the horizontal axis represents the monitoring angle of view. As shown in this figure, when the monitoring angle of view is determined, the position of the light transmission lens is uniquely determined.

  On the other hand, the zoom lens control unit 28 generates a drive signal for driving the zoom lens 121 arranged in the laser radar 1 so that the monitoring field angle of the light receiving unit 12 becomes the monitoring field angle acquired as input information. This drive signal is output to a zoom lens actuator (not shown). Thereby, the zoom lens 121 is moved to a position corresponding to the monitoring angle of view.

The synchronization control signal output from the control device 3 is supplied to the laser power source 26 and the shutter control unit 24 via the control signal conversion device 23 in the laser radar control unit 2.
When the synchronization signal is input, the laser power source 26 supplies power to the laser oscillator 111 in the light transmission unit 11 provided in the laser radar 1. As a result, laser light is continuously emitted from the laser transmitter 111.
On the other hand, the shutter control unit 24 drives the light transmission shutter 112 of the light transmission unit 11 and the light reception shutter 122 of the light reception unit 12 provided in the laser radar 1 in synchronization with each other based on the synchronization signal input from the control device 3.

Thereby, first, laser light which is continuous light is emitted from the laser oscillator 111 by power supply from the laser power source 26. The laser light is guided to a light transmission shutter 112 that is controlled to be opened and closed at a constant interval, thereby passing / blocking at a constant time interval and being converted into intermittent laser light. The intermittent laser light passes through the light transmission lens 112 whose position has been adjusted by the light transmission lens control unit 27 and is expanded so as to obtain an irradiation region suitable for the monitoring angle of view, and is emitted to the outside. The
The laser beam reflected by the object existing in the irradiation area is controlled to be opened and closed in synchronization with the light transmission shutter 112 through the zoom lens 121 of the light receiving unit 12 set to a predetermined monitoring field angle. The light is taken into the ICCD camera head 123 via the light receiving shutter 122. In this case, since the light transmitting shutter 112 and the light receiving shutter 112 are controlled to be opened and closed in synchronization with each other, the laser light is transmitted at the timing when the reflected light is taken into the ICCD camera head 123 as shown in FIG. The light can be emitted from the portion 11. Thereby, the laser beam emitted from the light transmitter 11 can be effectively utilized.

  Then, the light information captured by the ICCD camera head 123 is converted into an image signal that is an electrical signal and output to the image processing device 25 in the laser radar control unit 2. The image processing device 25 performs predetermined image processing on the image signal and outputs the image signal. An image signal from the image processing device 25 is input to the control device 3 via the control signal conversion device 23. The control device 3 outputs the input image signal to the display device 4. As a result, the outline of the object and the like are displayed on the display monitor of the display device 4 as visible information. Then, by confirming the image displayed on the display monitor by a monitor or the like, it is possible to acquire information such as the shape and size of the object existing in the irradiation region.

As described above, according to the monitoring apparatus according to the present embodiment, the irradiation area of the laser beam emitted from the light transmitting unit 11 is adjusted based on the monitoring angle of view specified from an input device (not shown). Therefore, as shown in FIGS. 4 and 5, it is possible to change the irradiation area in conjunction with the monitoring angle of view. That is, as shown in FIG. 4, when the monitoring angle of view is large, the irradiation area is also adjusted to be large in accordance with the monitoring angle of view, and as shown in FIG. 5, when the monitoring angle of view is small, the irradiation area. Is adjusted to be smaller in conjunction. And since an irradiation area | region is always adjusted to the range smaller than the area | region by a monitoring angle of view, useless light irradiation can be prevented and it becomes possible to monitor efficiently. As described above, since it is possible to irradiate light within a suitable range according to the monitoring angle of view, the image signal obtained by the light receiving means can be an image signal having an optimum image quality, and this image signal is displayed. By displaying on the device 4 or the like, it is possible to obtain a monitoring image with an optimum image quality.
Furthermore, according to the monitoring apparatus according to the present embodiment, the light transmission shutter 112 is opened and closed in synchronization with the opening and closing timing of the light receiving shutter 122, so that the irradiated laser beam can be minimized. This makes it possible to effectively use the irradiation energy of the laser light.
Further, by using a semiconductor laser as the laser oscillator 111, it is possible to reduce the size and cost of the entire apparatus while ensuring stable laser output.

  In the first embodiment described above, the light transmission shutter 112 is provided between the laser oscillator 111 and the light transmission lens 113, and the light transmission shutter 112 is controlled to be opened and closed in synchronization with the light reception shutter 122 included in the light receiving unit 12. Thus, the irradiation timing of the laser beam emitted from the light transmitting unit 11 is controlled. Instead, for example, the laser beam emission timing of the laser oscillator 111 is controlled by an electric signal synchronized with the light receiving shutter 122. It is also good to do. As described above, by controlling the laser light emission timing by the laser oscillator 111, the light transmission shutter 112 is not required, and the apparatus can be simplified. In the second embodiment to be described later, the light transmission shutter 112 can be made unnecessary by controlling the laser light emission timing by the laser oscillator 111.

[Second Embodiment]
Next, a monitoring apparatus according to the second embodiment of the present invention will be described. The monitoring device according to the present embodiment has a configuration substantially the same as the configuration of the monitoring device according to the first embodiment, but the monitoring device according to the first embodiment described above monitors from an input device (not shown). While the angle of view is input, the monitoring device according to the present embodiment is different in that a distance from an input device (not shown) to a monitoring target is input.
In this embodiment, based on the distance to the monitoring target, an optimal monitoring field angle and an optimal irradiation area of the laser beam are set and monitoring is performed. Hereinafter, the monitoring apparatus according to the present embodiment will be described with reference to FIG.

  First, when a distance from an input device (not shown) to the monitoring target is input, this distance is supplied from the control device 3 to the zoom lens control unit 28 in the laser radar control unit 2. The zoom lens control unit 28 sets a monitoring angle of view suitable for the distance based on the distance to the monitoring target. For example, the zoom lens control unit 28 has a table in which the distance to the monitoring target and the monitoring angle of view suitable for the distance are associated with each other, and the distance obtained as input information by referring to this table. Set the corresponding optimal monitoring angle of view.

FIG. 6 shows an example of a table in which the distance to the monitoring target is associated with the monitoring angle of view. As shown in this figure, the longer the distance to the monitoring target, the narrower the monitoring angle of view is set. This is because the reflection component of the laser light incident on the ICCD camera head 123 is reduced in monitoring a long distance, so that the angle of view must be narrowed and the amount of light incident on the camera must be maintained compared to the case of monitoring a short distance. Because there is.
When the zoom lens control unit 28 refers to such a table and sets the monitoring angle of view, the zoom lens control unit 28 generates a drive signal for moving the zoom lens 121 to a position corresponding to the monitoring angle of view, and zooms this. Supply to the lens actuator. Thereby, the zoom lens 121 is moved to a position corresponding to the monitoring angle of view.

On the other hand, the zoom lens control unit 28 outputs the set information of the monitoring angle of view to the light transmission lens control unit 27. Thereby, the light transmission lens control unit 27 controls the light transmission unit 11 so that the irradiation area by the light transmission unit 11 is an area suitable for the monitoring angle of view. Note that the processing of the light transmission lens control unit 27 is the same as described above.
Then, as described above, the monitoring angle of view is set based on the distance to the monitoring target, and an irradiation area suitable for this monitoring angle of view is set, so that as shown in FIG. The longer the distance, the narrower the angle of view for monitoring, and in conjunction with this, the irradiation area is set to a narrow range.

  As described above, according to the monitoring apparatus according to the present embodiment, the light receiving unit 12 is adjusted so as to obtain an optimal monitoring field angle based on the distance to the monitoring target, and further suitable for the monitoring field angle. Since the light transmission unit 11 is adjusted so that the irradiated area can be obtained, it is possible to perform optimum monitoring according to the distance to the monitoring target. Thereby, the image quality of the image displayed as the monitoring result can be optimized.

In the monitoring apparatus according to the second embodiment described above, a noise evaluation function (noise evaluation means) for performing noise evaluation of the image signal acquired by the light receiving unit 12 is added to the image processing apparatus 25, and this noise is added. Based on the evaluation result of the evaluation function, the monitoring angle of view and the irradiation area may be finely adjusted.
Specifically, in the above-described monitoring device, the image processing device 25 performs noise evaluation of the image signal acquired by the light receiving unit 12 while gradually changing the set monitoring angle of view and irradiation area step by step. Do. This noise evaluation is performed, for example, by obtaining an S / N (Signal to Noise ratio) ratio.
Then, when the S / N ratio obtained as a result of the noise evaluation exceeds a preset allowable noise value, the monitoring angle of view and the irradiation area at that time are adopted, and monitoring for the distance is performed. I will do it. Alternatively, the S / N ratio when the monitoring angle of view and the irradiation area are changed step by step is accumulated, and the irradiation area and the monitoring angle of view when the S / N ratio is the highest among them are adopted. We will monitor the distance.
As described above, by adjusting the monitoring angle of view and the irradiation area based on the noise evaluation result, it is possible to reduce the noise of the monitoring image and obtain a monitoring image with high image quality.

Further, when monitoring is performed by the above-described first or second monitoring device, for example, as shown in FIG. 8, if rain or mist is generated in the laser light irradiation range, light is affected by these effects. The problem arises that the information to be monitored cannot be obtained accurately due to scattering.
Therefore, as shown in FIG. 9, when there is a region that generates scattered light in the laser light irradiation range, the light transmission unit 11 and the light transmission unit 11 are not included in the monitoring field angle of the light receiving unit 12. You may make it adjust arrangement | positioning with the light-receiving part 12. FIG. By doing in this way, the influence of the scattered light by rain, fog, etc. can be avoided, and the reflected light from the monitoring object A can be taken in easily.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
For example, in the monitoring apparatus according to the first or second embodiment described above, a shake correction function may be added to the laser radar 1 or the turntable 5. In this way, by adding the shake correction function, for example, it is possible to prevent problems such as the laser radar 1 vibrating due to the influence of wind or the like and the image acquired by the light receiving unit 12 being out of focus. A high-quality monitoring image can be obtained.

It is the block diagram which showed schematic structure of the monitoring apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the table which matched the monitoring angle of view and the light transmission lens position. It is a figure for demonstrating the opening / closing timing of a light-receiving shutter and a light transmission shutter. It is the figure which showed an example of the irradiation area | region of the laser beam in case a monitoring angle of view is wide. It is the figure which showed an example of the irradiation area | region of the laser beam in case a monitoring field angle is narrow. It is the figure which showed an example of the table which matched the distance to the monitoring object, and the monitoring angle of view in the monitoring apparatus which concerns on the 2nd Embodiment of this invention. In the monitoring apparatus which concerns on the 2nd Embodiment of this invention, it is the figure which showed the change with the monitoring angle of view at the time of changing the distance to monitoring object, and the irradiation area | region of a laser beam. It is explanatory drawing shown about the scattered light resulting from rain or fog. It is the figure which showed an example of the positional relationship of arrangement | positioning of a light transmission part and a light-receiving part when there exists an area | region which produces a scattered light in the irradiation range of a laser beam. It is explanatory drawing shown about the conventional monitoring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser radar apparatus 2 Laser radar control part 3 Control apparatus 4 Display apparatus 5 Turntable 11 Light transmission part 12 Light reception part 21 Turntable drive part 23 Control signal conversion apparatus 24 Shutter control part 25 Image processing apparatus 26 Laser power supply 27 Light transmission lens Control unit 28 Zoom lens control unit 111 Laser oscillator 112 Light transmission shutter 113 Light transmission lens 121 Zoom lens 122 Light reception shutter 123 ICCD camera head

Claims (4)

Light transmitting means that emits laser light, and light reception that receives the reflected light reflected by the light emitted from the light transmitting means reaching the object to be monitored, and converts the captured reflected light into an image signal for output A monitoring device comprising means,
A monitoring apparatus comprising light transmission control means for adjusting an irradiation area of the light transmission means based on a monitoring field angle of the light receiving means. The light receiving means is provided on the optical path of the reflected light, and has a light receiving shutter that opens and closes at a predetermined timing;
The light transmitting means is
A laser light source that emits continuous light;
The monitoring device according to claim 1, further comprising: a light transmission shutter provided on an optical path of continuous light emitted from the laser light source and opened and closed in synchronization with opening and closing of the light receiving shutter.   The monitoring apparatus according to claim 1, further comprising a light receiving control unit that adjusts a monitoring field angle of the light receiving unit based on a distance to the monitoring target. Evaluating means for performing noise evaluation of the image signal output from the light receiving means,
The light transmission control unit and / or the light reception control unit adjusts an irradiation area of the light transmission unit and / or a monitoring angle of view of the light reception unit according to a result of noise evaluation by the evaluation unit. The monitoring device described.

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